LAGOS, Nigeria (AP) — Shaking a finger while cradling an assault rifle, the bearded leader of Nigeria’s extremist Islamic sect threatens to burn down more schools and kill teachers. But he denies his fighters are killing children.

In a new video released Saturday, Islamic radical Abubakar Shekau said he “fully supports” attacks on several schools in northeastern Nigeria in recent weeks.

The United Nations Children’s Fund says at least 48 students and seven teachers have been killed since June, with some burned alive in a dormitory this month.

“We support the work they did at the school, at Mamudo and Damaturu, and other attacks in other schools,” said Shekau, who wore military fatigues in the video. “We are going to burn down the schools, if they are not Islamic religious schools for Allah.”

But Shekau insisted his fighters do not kill children.

“We don’t touch small children, we only burn the schools,” he says. “Our religion does not permit us to touch small children and women, we don’t kill children.”

He said his fighters would, however, attack teachers. “School teachers who are teaching Western education? We will kill them! We will kill them!” he warns, wagging his finger.

Shekau is a leader of the extremist group Boko Haram, whose name means “Western education is forbidden” in the Hausa language.

Attacks on schools have continued although thousands of troops have deployed in northeastern Nigeria to put down the Islamic extremists’ violent campaign which poses the greatest threat in years to the security of Nigeria, Africa’s biggest oil producer.

President Goodluck Jonathan declared a state of emergency on May 14 in the three northeastern states of Adamawa, Borno and Yobe.

In northwestern Nigeria this week, security forces said they engaged in a five-hour gunbattle against a group of Boko Haram fighters in Sokoto. The city is home to the Sultan of Sokoto, the pre-eminent leader of Nigeria’s tens of millions of Muslims, who preaches against extremism and who has condemned Boko Haram.

Police said they recovered a weapons cache including assault rifles, grenades, rocket launchers and homemade bombs.

There has been no attack on Sokoto since July 30 last year, when suicide bombers in cars laden with explosives simultaneously attacked a police station and the regional police headquarters. The two bombers and at least three other people were killed. At the time, Boko Haram threatened to assassinate the sultan.

Recently, the extremists have started targeting civilians, especially government workers, Christian pastors, school teachers and their students.

In the video, received by The Associated Press through intermediaries, Shekau also denied he is negotiating a peace agreement with the Nigerian government.

“We will not enter into any agreement with non-believers or the Nigerian government,” he said, speaking in his native Hausa.

“The Quran teaches that we must shun democracy, we must shun Western education, we must shun the constitution,” Shekau said in the 15-minute video.

At the end, he speaks in English to denounce the West, accusing it of trying to destroy Islam and working “to tactically make the Quran insignificant and unimportant.”